Kenji Masunaga

Kurume University, Куруме, Fukuoka, Japan

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Publications (7)8.79 Total impact

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    ABSTRACT: A methicillin-resistant Staphylococcus aureus (MRSA) outbreak occurred in an advanced emergency medical service center between 2010 and 2011. Our objective was to evaluate the status of the MRSA outbreak, as monitored by molecular analysis. Twenty-eight MRSA strains were isolated from blood samples from 11 patients, from other specimens (pharynx, nasal cavity, etc.) from 12 patients, from two environmental samples, and from the skin, middle nasal meatus, and urine of one patient each from other wards. Pulsed-field gel electrophoresis (PFGE) was performed to evaluate horizontal transmission. Molecular typing by PFGE showed that the 28 MRSA strains presented 7 patterns in total, and that 11 of the MRSA strains had the same PGFE pattern. Unselective use of intranasal mupirocin ointment, MRSA monitoring for new inpatients, and prevention of direct or indirect contact infection were performed. However, the number of inpatients with MRSA did not quickly decrease, and additional molecular typing by PFGE showed that 10 of 19 MRSA strains found (5 of 6 from blood, 5 of 13 from other specimens) were the same as those found previously. Lectures and ward rounds were performed repeatedly, and staff participation in ward rounds was suggested. Finally, the number of inpatients with MRSA significantly decreased more than 6 months after the intervention. Although the MRSA outbreak was thought to have ended, follow-up molecular typing by PFGE showed that horizontal transmission persisted. Our data suggest that various combinations of infection control measures are essential when dealing with an MRSA outbreak, and monitoring by molecular analysis using PFGE is useful to identify the status of the outbreak.
    Journal of Infection and Chemotherapy 03/2013; · 1.55 Impact Factor
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    ABSTRACT: Hospital renovation projects pose risks of invasive infection by fungi from dust that is blown about during the period in question. Control measures to reduce the amount of dust during hospital renovation are thus necessary. Currently, no study has compared different control measures for effectiveness through more than one period of renovation. In this study, we examined the capacities of two control measures of weatherstripping (0.15 mm poly film and adhesive tape) to reduce the amount of blowing dust during two different hospital renovations (in 2008 and 2009). The amount of dust in the air of the hospital before and during the renovation was measured about once a week in both 2008 and 2009, and the between-year and within-year differences were tested. Our study revealed that the weatherstripping used in 2009 (adhesive tape) was significantly more effective than the measures taken in 2008 (0.15 mm poly film) to reduce the amount of dust during the renovations (p < 0.001), while in both years the amount of dust became significantly higher during the renovations than before the renovations. Differences in the effectiveness of weatherstripping during renovations between floors of the hospital were not significant in both 2008 and 2009. The number of Aspergillus-positive samples did not significantly increase compared with the number observed before the start of the hospital renovations (2006-2007) in 2008 and 2009, respectively. The weatherstripping potentially reduced the associated risk of airborne fungal infection.
    Journal of Infection and Chemotherapy 10/2010; 16(6):431-5. · 1.55 Impact Factor
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    ABSTRACT: A 54-year-old Japanese man without underlying disease developed pneumococcal bacteremia and meningitis after traveling to the Philippines. The isolate demonstrated high affinity to the lung and invasiveness in vivo. The international travelers can import indigenous high virulent strains even if the bacterium is commonly isolated in the home country.
    Journal of Travel Medicine 01/2010; 17(1):63-5. · 1.68 Impact Factor
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    ABSTRACT: Adrenocorticotropic hormone (ACTH) has been the first-line drug for the treatment of West syndrome, although the therapy has various adverse effects. ACTH depresses resistance to a variety of bacterial, viral, protozoal, and fungal agents. The timing of the various vaccinations is delayed after ACTH therapy in Japan, because the immune system is believed to be affected for approximately 6 months. However, the duration of the effect of ACTH on the immune system is not known. Therefore, we examined changes in the immunity levels before and after ACTH therapy. We measured white blood cell counts, lymphocyte counts, T/B cell counts, CD4(+) and CD8(+) T cell counts, CD 4/8 ratio, lymphocyte blastoid transformation by PHA or Con-A, and the levels of IgA, IgM, and IgG before, immediately after, and 1, 3, 6, and 12 months after ACTH therapy. The lymphocyte counts and CD4(+) T cell counts were significantly decreased immediately after and at 1 and 3 months after the therapy, and did not return to the previous levels even at 6 months and 12 months after ACTH treatment; however, these levels returned to within normal limits (within the 95% confidence interval). Immunoglobulin levels did not change after the ACTH therapy. Helper T cells were more depressed than cytotoxic T cells after ACTH therapy.
    Brain & development 01/2009; 31(10):739-43. · 1.74 Impact Factor
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    ABSTRACT: Streptococcus bovis very occasionally causes rarely sepsis, endocarditis, and meningitis in newborns and the elderly. We report the case of infant meningitis caused by S. bovis despite normal cerebrospinal fluid (CSF) findings at the first CSF examination. A 77-day-old boy with 21-trisomy and patent foramen ovale and seen for a high fever underwent blood examination and lumbar puncture due to toxic appearance despite a lack of meningeal signs, and was admitted. His CSF findings were normal and he was given intravenous ceftriaxone against potential bacteremia. He had systemic seizures with continuous fever for 2 days after admission and a second CSF examination. Gram-positive coccus grew from his CSF at the first examination, and CSF cells from the second lumbar puncture increased to 4060/tL (86% neutrophils), so vancomycin was added against potential enterococcal meningitis. S. bovis was finally grown from the first CSF, ceftriaxone discontinued, and intravenous ampicillin added. He recovered after 20 days of antibiotic administration. S. bovis becomes a potential pathogen for meningitis in infants, and must be considered as a cause of meningitis despite its very rarity. CSF findings at the first lumbar puncture may be normal for meningitis in newborns and infants at the first CSF examination, so we must be very careful in the diagnosis of bacterial meningitis even with normal CSF findings, and considered antibiotic treatment against potential bacterial meningitis.
    Kansenshogaku zasshi. The Journal of the Japanese Association for Infectious Diseases 02/2008; 82(1):26-9.
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    ABSTRACT: MICs of penicillin G, erythromycin, clarithromycin, clindamycin, azithromycin, and telithromycin were tested for 189 clinical isolates collected during 2002 to 2005 from children in southwestern Japan. Serotyping and polymerase chain reaction for presence of erm(B) and mef(A) were performed. All strains with erm(B) + mef(A) were analyzed by pulsed-field gel electrophoresis (PFGE) and compared to 3 global clones: Spain(23F)-1; Spain(9V)-3 and its variant -14; a South Korean strain same as Taiwan (19F)-14 clone and 5 strains with erm(B) + mef(A) from other countries. Of the 173 macrolide-resistant (erythromycin MIC > or =0.5 microg/mL) strains, 104 (60.1%) had erm(B), 47 (27.2%) had mef(A), and 22 (12.7%) had erm(B) + mef(A). Strains expressing erm(B) or both erm(B) and mef(A) had high macrolide MIC(90)s (>64 microg/mL), except telithromycin (MIC(90), 0.25 microg/mL). Of the 22 erm(B) + mef(A) strains, 10 had 4 distinct PFGE patterns and were mainly serotype 6B clones, which differed from those described in previous reports; 5 other strains had unique profiles.
    Diagnostic Microbiology and Infectious Disease 01/2008; 62(1):16-22. · 2.26 Impact Factor
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    ABSTRACT: Dipylidium caninum, the dog tapeworm, is a common intestinal cestode of domestic dogs and cats, but few cases have been reported of human infection by this parasite in Japan. We repot a case of D. caninum infection in a 17 month-old girl, who sometimes had symptoms of abdominal pain, diarrhea, and dysphoria at night. Her mother noted the appearance of small white worms in her stool, and she was seen by a local pediatrician. Despite antiparasitic therapy wiht pyrantel pamoate, the problem persisted and was eventually referred for further workup to Kurume University Hospital. The diagnosis was made by microscopic examination of the excreted proglottids, which contained characteristic egg capsules. She was successfully treated with a singledose of praziquantel and four adult parasites were recovered. The longest intact worm was 32cm. Her family had household pets (a dog and a cat). The pets were seen by the local veterinary and both were evidenced D. caninum. Humans, primarily children, become infected when they accidentally ingest fleas. Parents usually find proglottids as multiple white objects, often described as cucumber, melon, or pumpkin seeds, in stool, diapers, or on the perineum. Most general practitioners and pediatricians may treat children with enterobiasis (pinworm) infection, and in case the treatment fails, other parasite infection should be considered such as this worm. A history of dog or cat pets, fleas, and flea bites may be important clues to diagnosis. Pets found to be infected should also be treated.
    Kansenshogaku zasshi. The Journal of the Japanese Association for Infectious Diseases 08/2007; 81(4):456-8.